The proposed studies aim to: 1) define the colonic myoelectric patterns of recovery from postoperative paralytic ileus and to determine if pharmacologic manipulations can shorten the duration of ileus; 2) define the "normal" myoelectrical patterns of the human colon displayed under resting conditions in response to a meal and after the administration of various pharmacologic agents; 3) characterize abnormalities of colonic myoelectric activity in patients with diverticulosis of the colon, and insulin dependent diabetes. Most previous studies of colonic myoelectric activity in humans were based on observations derived from the use of suction electrodes, recording from the distal part of the sigmoid colon. The proposed work will employ a novel approach which will combine the use of subserosally implanted electrodes and telemetric transmission of colonic myoelectric signals. This approach will allow continuous monitoring of myoelectric activity of the intra-abdominal colon with minimal discomfort to the patient. Our methods include: a) the implantation of teflon coated electrodes at nine different sites along the length of the colon; b) the use of a small, light weight receiver-transmitter worn externally by the patient and connected to the free ends of the implanted electrodes; c) a telemetric system consisting of a central receiver capable of demultiplexing the signals generated by the colonic smooth muscle; and d) a multichannel chart recorder and digital tape deck for recording and storage of data for visual and computer analysis. The following parameters will be used for the analysis of colonic myoelectric activity: a) percentage of total recording time (for each channel) during which slow waves and spike bursts are present; b) slow wave frequency and power spectrum in different parts of the colon; c) relation of slow waves and spike bursts; d) duration of individual spike burst; e) duration of clusters of spike burst; f) migration direction (orad or aborad) of spike bursts, singly or in clusters, and g) migration velocity. It is anticipated that our observations will better define the myoelectric activity displayed by the colon in health and disease.